Method for producing liquid fertilizer

Abstract: Method for producing liquid fertilizer is characterized in that raw material made of human waste consisting of feces and urine is made to come into contact with heated animal oil, plant oil, mineral oil or a mixture of these oils under a reduced pressure, and water contained in the raw material is evaporated from the raw material and moisture made of evaporated water is collected, cooled and liquefied to produce liquid fertilizer.

Description: BACKGROUND OF INVENTION This invention relates to a method for producing liquid fertilizer. Conventionally, the treatment of human feces and urine or other wastes in a sludge form has necessitated a huge amount of expenses. Especially, in case of raw material made of human waste consisting of feces and urine, since the water content of the raw material is approximately 97 percent, the moisture or vapor produced by burning the raw material includes malodors. Accordingly, the moisture is drained by way of an expensive deodorizing treatment and thereafter is discharged into the river or sea. Sewage sludge, garbage discharged from kitchen, garbage from food plant, or waste made of internal organs, bones, blood of animals and fish also requires a considerable expense for the treatment thereof, wherein the treatment varies corresponding to the kind of raw material and each treatment is cumbersome and time-consuming. Eventually the treatment of the raw material as known for instance from US-A-4536412, produces mainly the powdery solid fertilizer or forage so that the production of the liquid fertilizer further necessitates a separate or additional liquefying treatment. Also, since the treatment of the raw material made of human waste requires a considerable expense, the scattering of the raw material in the ocean is still continuing. Accordingly, there is a demanding need for a method which can effectively treat the raw material made of human waste. It is an object of this invention as claimed in the appended Claim, whose preamble is based on US-A-4536412. In one embodiment of this invention, approximately 1000 kg of raw material made of human waste consisting of feces and urines is charged into a cooker having a capacity of 7 m3 which preliminarily stores approximately 800 kg of animal oil, plant oil or mineral oil heated at a temperature of 70° C - 150 ° C. Simultaneously, or after a lapse of a predetermined time (approximately 1 hour and a half to 3 hours), the inside of the cooker is made to be under reduced pressure (from the normal pressure to approximately 500 to 700 mmHg) (6.66·10 4 Pa to 9.33·10 4 Pa). Due to the pressure reducing and heating, the water components contained in the raw material made of human waste is evaporated to become vapor and fills in the cooker. The vapor is continuously extracted or taken out from the cooker and is cooled by a condenser and drained to produce liquid. This liquid is directly used as liquid fertilizer or water soluble nitrogen is added to the liquid to produce liquid fertilizer for hydroponics, while the raw material made of human waste is dehydrated making use of the oil in the cooker and the dehydrated human waste is taken out from the cooker and oil component is removed therefrom so as to produce fertilizer or forage in a cake form containing high percentage of protein. Sewage sludge, garbage discharged from kitchen, garbage from food plant, or waste made of internal organs, blood or bones of animals also can be heated and dehydrated in the cooker in the same manner under a reduced pressure and the vapor is cooled and drained to produce liquid fertilizer, while the raw material is dehydrated to produce fertilizer or forage in a powder or cake form containing high percentage of protein. BRIEF EXPLANATION OF DRAWINGS Fig 1 is a partially broken side view of a device used for the method of this invention for producing the liquid fertilizer. DETAILED DESCRIPTION OF DISCLOSURE The invention is explained in view of attached drawings. Fig. 1 is an illustration of an apparatus suitable for carrying out the method of producing liquid fertilizer of this invention. Numeral 1 indicates a cooker. Agitating blades 2 are rotatably disposed in the cooker 1 while numeral 3 indicates a rotary shaft for supporting agitating blades 2. In the peripheral wall of the cooker 1, a jacket portion 4 is formed and pressurized steam is filled in the jacket portion 4, the rotary shaft 3 and the agitating blades 2. Numeral 5 indicates a pressurized steam inlet provided for charging pressurized steam into the jacket portion 4. In the cooker 1, animal oil, plant oil, mineral oil or a mixture of these oils L is filled, while the various oil in the cooker 1 is heated by means of steam charged in the jacket portion 4, the rotary shaft 3 and the agitating blades 2 under pressure. Numeral 6 indicates an air bleed port provided at the peripheral wall of the cooker 1, wherein the air in the cooker 1 is discharged through the air bleed port 6 so as to reduce the pressure in the cooker 1. Numeral 7 indicates a raw material feeding port which is disposed at a position below the surface of the oil stored in the cooker 1, and this raw material feeding port 7 is communicated with a raw material feeding pipe 8, which, in turn, is provided with a valve 9 in the midst thereof for allowing or stopping the supply of raw material. The raw material feeding pipe 8 has the proximal end thereof communicated with a raw material hopper 10. The raw material made of human waste consisting of feces and urines, or sewage sludge, garbage discharged from kitchen, garbage from food plant, or waste made of internal organs, blood or bones of animals is filled in the raw material hopper 10 and is fed to the cooker 1. Numeral 11 indicates a discharge outlet provided for discharging the processed raw material. Apart from the air bleed port 6, the cooker 1 is provided with a vapor outlet 12 on the peripheral wall thereof which is communicated with a vapor take-out pipe 13, which, in turn, has the proximal end thereof communicated with a condenser 14 so that the vapor extracted or taken out is cooled and drained to produce liquid which is stored in a liquid fertilizer tank 15. The method of this invention is carried out in a following manner with the above-mentioned device, wherein human waste consisting of feces or urines is used as raw material. The raw material is filled in the cooker 1, which, is preliminarily filled with animal oil, plant oil, mineral oil or a mixture of these oils L and the heated steam is filled in the jacket portion 4 formed in the peripheral wall of the cooker 1 under pressure. The raw material M is subject to the oil in the cooker 1 and, therefore, is heated by the oil temperature. After charging the raw material M in the cooker 1, the inside of the cooker 1 is made to be pressure-reduced. The pressure reducing conditions are in three forms, wherein the first pressure reducing condition is that a pressure of 500 mmHg - 700 mmHg (6.66·10 4 Pa - 9.33·10 4 Pa) in the cooker 1 is reduced from a normal pressure while the heating condition is set at a temperature which falls within a range of 70° C - 150 ° C which is suitably determined corresponding to the kind of bacteria being contained in the liquid fertilizer. The second pressure reducing condition is that the pressure is reduced in two stages after the charging of the raw material, wherein the initial stage, a pressure of 20 - 100 mmHg (2.66·10 3 Pa - 1.33·10 4 Pa) is reduced from the normal pressure for 30 minutes, and in the subsequent stage, a pressure of 700 - 750 mmHg (9.33·10 4 Pa - 9.99·10 4 Pa) is reduced for 1 - 2 hours from the pressure reduced in the initial stage. The third pressure reducing condition is that the pressure is reduced in three stages from the normal pressure after the charging of the raw material, wherein in the initial stage, a pressure of approximately 200 mmHg (2.66·10 4 Pa) is reduced from the normal pressure for 5 to 10 minutes, and in the intermediate stage, a pressure of 300 mmHg - 400 mmHg (3.99·10 4 Pa - 5.33·10 4 Pa) is reduced from the pressure reduced in the initial stage approximately for 20 minutes, and in the final stage, a pressure of 250 mmHg - 500 mmHg (3.33·10 4 Pa - 6.66·10 4 Pa) is reduced approximately for 1 hour to 1.5 hours. Consequently, inside the cooker 1 is approximately evacuated. In this manner, upon heating the raw material M made of human waste with the heated oil in the cooker 1 under a predetermined reduced pressure condition, water component contained in the raw material is dehydrated and a considerable amount of water is vaporized from the raw material of high water component rate. Furthermore, water contained at the core of the raw material is replaced with oil due to the difference of specific gravities between water and oil under the reduced pressure so that the heated oil is infiltrated into the core while the water contained in the core is vaporized. In this manner, water component vaporized from the raw material in the cooker 1 is taken out from the vapor outlet 12 and is fed to the condenser 14. In the condenser 14, the vapor taken out from the cooker 1 is cooled and drained to produce liquid N which is to be collected. The collected liquid N contains various bacteria which are contained in the human waste consisting of feces and urines as organic fertilizer components and the liquid also contains nitrogen, phosphate and potassium. The liquid can be directly used as liquid fertilizer in the water cultivation, while the solid components remained in the oil in the cooker 1 is dehydrated as dehydrated residue or squeezed to produce powdery fertilizer or forage of high protein content. The drained liquid is directly used as liquid fertilizer or is added with water soluble nitrogen to produce liquid fertilizer. The temperature of the oil is determined in view of the pressure reducing conditions, wherein in the previously mentioned first reduced pressure condition, the heating is carried out with the oil temperature of 70° C to 150° C. In the second reduced pressure condition, the oil temperature is set at 40 ° C to 50 ° C at the initial reducing pressure and the oil temperature is set at 50 ° C to 70 ° C at the subsequent reduced pressure. In the third reduced pressure condition, the oil temperature is set at 60° C to 70 ° C at the initial reducing pressure and the oil temperature is set at 50° C to 60° C at the intermediate reducing pressure and the oil temperature is set at 60° C to 65° C at the final reduced pressure. In other embodiments, sewage sludge, garbage discharged from kitchen, garbage from food plant or waste made of internal organs, bones, blood of animals and fish can be used. These raw materials are charged in the animal oil, the plant oil, the mineral oil heated in the cooker in the same manner as that of the raw material made of human waste and dehydrated and heated by oil temperature under a reduced pressure. Then, the vapor generated at the time of dehydration of the raw material is fed to the condenser and is cooled and drained to produce the liquid fertilizer. The pressure reducing conditions and heating temperature are the same as those of the previous embodiment. According to this invention, since the raw material of high water content is treated with temperature of heated oil and vapor is taken out therefrom and is drained to be used as liquid fertilizer, the drain is free of malodor, while the collected vapor from the raw material contains nitrogen, phosphate and potassium, components of organic fertilizer such as various bacteria which are contained in the human waste consisting of feces and urines and the water soluble protein. Accordingly, such vapor can be used as organic fertilizer having high quality. Especially, since the raw material made of human waste consisting of feces and urines contains water at high percentage, a considerable amount of drain can be collected, while the processing of the raw material made of human waste per se can be simultaneously carried out. Namely, the production of the liquid fertilizer as organic fertilizer and the treatment of the raw material made of human waste are simultaneously carried out.

Claims: Method for producing fertilizer, of the type wherein a water containing raw material is made to come into contact with heated animal oil, plant oil, mineral oil or a mixture of these oils in a cooker under specific pressure and temperature conditions, and water contained in the raw material is evaporated from the raw material, characterized in that a) the raw material is selected in the groups of human waste consisting of feces and urine ; sewage sludge, garbage discharged from kitchen ; garbage from food plant, or waste made of internal organs, bones, blood of animals and fish; b) the raw material is made to come into contact with oil under pressure reducing conditions, which are in three forms, namely : the first pressure reducing condition is that a pressure of 6.66· 10 4 Pa - 9.33·10 4 Pa (500 mmHg-700 mmHg) in the cooker 1 is reduced from a normal pressure while the heating condition is set at a temperature which falls within a range of 70°C-150°C which is suitably determined corresponding to the kind of bacteria being contained in the liquid fertilizer ; the second pressure reducing condition is that the pressure is reduced in two stages after the charging of the raw material, wherein the initial stage, a pressure of 2.66·10 3 Pa - 1.33·10 4 Pa (20-100 mmHg) is reduced from the normal pressure for 30 minutes, and in the subsequent stage, a pressure of 9.33·10 4 Pa - 9.99·10 4 Pa (700-750 mmHg) is reduced for 1-2 hours from the pressure reduced in the initial stage ; the third pressure reducing condition is that the pressure is reduced in three stages from the normal pressure after the charging of the raw material, wherein in the initial stage, a pressure of approximately 2.66·10 4 Pa (200 mmHg) is reduced from the normal pressure for 5 to 10 minutes, and in the intermediate stage, a pressure of 3.99·10 4 Pa - 5.33·10 4 Pa (300 mmHg-400 mmHg) is reduced from the pressure reduced in the initial stage approximately for 20 minutes, and in the final stage, a pressure of 3.33·10 4 Pa - 6.66·10 4 Pa (250 mmHg-500) mmHg is reduced approximately for 1 hour to 1.5 hours ; and c) moisture made of evaporated water is collected, cooled and liquefied to produce liquid fertilizer.

Inventors: NAKAZONO SHUZO, NAKAZONO, SHUZO
Applicants: NAKAZONO SHUZO, NAKAZONO, SHUZO
Application year: 1994
Main classification: C05F3
IPC codes: C05F7, C05F3, C05F9, C05G3, C05F1, C05G5